1. Field of the Invention
The present invention relates to an apparatus for cleaning and drying substrates. More particularly, the present invention relates to an apparatus and method for cleaning substrates such as semiconductor wafers and LCD glass panels by sinking the substrates into cleaning fluids and then drying the substrates.
2. Discussion of the Related Art
A substrate cleaning method that is widely adopted in semiconductor manufacturing processes includes sinking the substrates such as semiconductor wafers and LCD glass panels into treatment tanks consecutively. The treatment tanks are filled with cleaning fluids such as cleaning chemicals or rinsing liquids.
After the wafers being treated for cleaning as above, a drying process generally follows for removing or drying water on the wafer surface. In well known drying method, vapors of volatile organic chemical such as isopropyl alcohol are provided toward the substrate such that the vapors, being condensed and deposited on the surface of the substrate, remove waters thereon, hence drying the substrate.
An apparatus for cleaning and drying substrates has been disclosed in Korea publication patent 1999-7018 wherein two chambers, a cleaning chamber and a drying chamber, were integrated into a single chamber, the drying chamber being positioned above the cleaning chamber, such that both the cleaning and drying process could be carried out in the single chamber.
The cleaning and drying apparatus has discharge openings on fixed locations, on both of the lower sides of the drying chamber, the discharge openings for evacuating the inert gas and volatile organic chemical from the drying chamber. With the discharge openings formed on both sides of the drying chamber, flow irregularity arouses: the gas flow diverges toward each discharge opening near the bottom of the drying chamber, and accordingly the gas flow becomes weaker at the center region. Due to the flow irregularity, it takes longer time to evacuate the inert gas and volatile organic chemical from the drying chamber, and hence the efficiency of the drying process deteriorates. In addition, the pressure of the drying chamber being higher than that of the cleaning chamber (the pressure of the drying chamber and the cleaning chamber are different from each other), it is hard to induce a strong gas flow along the surfaces of the substrates.